Directions:

Make the Leaven:

The night before you plan to make the dough, put the matured sourdough from your refrigerator in water, and add flours. Mix well so you don't have any lumps of dry flour. Cover with a tea towel. Let rest on the counter for 8-10 hours. To test leaven's readiness, drop a spoonful into a bowl of room-temperature water. If it sinks, it is not ready and needs more time to ferment and ripen. If it floats, it's ready to use. As it develops, the smell will change from ripe and sour to sweet and pleasantly fermented.

Make the Dough:

Pour 700 grams warm water into a large mixing bowl, add 200 grams leaven, stir to disperse. (Save your leftover leaven. It will be your starter/sourdogh for next time you bake.) Add flours and mix dough with your hands until no bits of dry flour remain. Let rest covered with a tea towel on your counter for 30 minutes. Add salt and remaining 50 grams warm water. Transfer to a medium plastic container or a glass bowl. Cover with kitchen towel. Let rest for 30 minutes.

Folding:

The dough will now begin its first bulk fermentation (rise), to develop flavor and strength. The rise is temperature sensitive. As a rule, warmer dough ferments faster. Robertson tries to maintain the dough at 78℉ to 82℉ to accomplish the bulk fermentation in 3 to 4 hours. (Normally It takes 3 hours at my house, even when I have the air-con on.)

Instead of kneading, Robertson uses a folding technique to develop the gluten structure in the dough. Fold dough, repeating every 30 minutes for about 2½ to 3 hours. To do a fold, dip 1 hand in water to prevent sticking. Grab the underside of the dough, stretch it out, and fold it back over itself. Rotate container one-quarter turn, and repeat. Do this 2 or 3 times for each fold. After the 3 hours, the dough should feel aerated and softer, and you will see a 20 to 30 percent increase in volume. If not, continue bulk fermentation for 30 minutes to 1 hour more.

Pull dough out of container using a dough spatula onto an unfloured surface. Lightly flour the surface of the dough and use a bench knife to cut the dough into 2 equal pieces. As you cut the first piece, use the bench knife to flip it, so the floured side now rest on the work surface. Do the same with the second piece of dough.

Working with the dough you want to incorporate as little flour as possible. Work each piece into a round using scraper and 1 hand. Tension will build as the dough slightly anchors to the surface as you rotate it. By the end, the dough should have a taut, smooth surface. Dust tops of rounds with flour, cover with a tea towel, and let rest on the work surface for 20 to 30 minutes. During this stage, (bench rest), each round will relax and spread into a thick pancake shape. The edges should appear fat and rounded, not flat or "dripping" of the edge. if the dough is flat or the dough is spreading too much, the dough has not developed enough strength during the bulk fermentation. To correct this, shape the dough into a round a second time and let it sit to rest covered once more.

The final shaping:

To form the loafs, carefully place a dough round onto a lightly floured surface with the floured side down, using the bench knife. Now the underside is facing up.

Be careful not to deflate the dough. This final shaping builds up tension inside each loaf, so it holds it's form and rises substantially when baked. This is called "oven spring."

Fold the third of the dough closest to you up and over the middle third of the round. Stretch out the dough horizontally to your right and fold this right third over the center. Stretch the dough to your left and foldt this third over the previous fold. You are now starting to get a neat package. Stretch out the third of the dough farthest from you and fold this flap toward you, over the previous folds, and anchor it in place with your fingers. Then grab the dough nearest to you and wrap it up and over, while rolling the whole package away from you, that the smooth underside of the loaf now is on the top and all the seams are on the bottom. Let the shaped loaf rest on the counter for a minute. Fold the other loaf the same way.

Line 2 baskets with clean tea towels; generously dust with rice flour. Using the dough scraper, transfer each round to a basket, smooth side down, with seam centered and facing up. Let rest at room temperature (75℉ to 80℉), covered with towels for 3 to 4 hours before baking.

Baking the Bread:

Twenty minutes before you are ready to bake the bread, preheat oven and dutch/french oven to 500 degrees, with rack in lowest position.

Flip one bread into heated dutch/french oven. Score top twice using a razor blade matfer lame. Cover with lid. Return to oven, and reduce oven temperature to 450℉. Bake for 20 minutes.